Wang Yang, a researcher at the Northeast Institute of Geography and Agroecology of the Chinese Academy of Sciences, talks about soil erosion control

Source: People's Daily - Jilin Channel Original draft

Editor's note: July 22 is the "Black Soil Protection Day" in Jilin Province, black soil is a valuable non-renewable soil resource, and black soil in Northeast China occupies a pivotal position in national grain production. In recent years, Jilin Province has kept in mind the entrustment, deeply promoted the implementation of the strategy of "hiding grain in the land, hiding grain in technology", taking the protection of black land as an important starting point, comprehensively implementing practical measures, vigorously grasping implementation, continuously improving the inherent quality, facility conditions and ecological environment of black soil arable land, and continuously consolidating the foundation of national food security, providing effective "Jilin experience" for black land protection.

Interview guest: Wang Yang, researcher at the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences

People's Daily News: Where in Jilin Province there is a problem of soil erosion? What are the experiences and practices of various localities to solve this problem?

Wang Yang: The types of soil erosion in Jilin Province are mainly based on two categories: hydraulic erosion and wind erosion. In the central and eastern regions, which are dominated by typical black soil, white pulp soil and brown soil, the climate is humid, the rainfall is large, and the plains, hills and terraces are the main landform types, which are prone to hydraulic erosion; in the western region, which is dominated by black calcium soil, the climate is arid, windy and rainy, the evaporation is large, and the aeolian sand saline alkali land and degraded meadows are the main landform types, which are prone to wind erosion. In 2019, the area of soil erosion in the province was about 41,756.99 square kilometers (area above mild erosion), accounting for 21.95% of the total area, of which the area of hydraulic erosion was 29,697.78 square kilometers, accounting for 71.1% of the total loss area, and the area of wind erosion was 12059.21 square kilometers, accounting for 28.9% of the total loss area. The organic matter content of the black soil tillage layer in Jilin Province has dropped from 4-6% before reclamation to 1.5-3%, and the soil nitrogen and phosphorus nutrient reserves have decreased by 30-60% and 16-24% respectively; the soil humus layer has dropped from 40-60 cm in the 1950s to 20-30 cm, and even more than 3% of the arable land humus layer has completely disappeared into "broken skin yellow". The degradation of black soil directly leads to poor physical, chemical and biological structure of soil, poor development of crop roots, weakening of nutrient absorption capacity and decreased soil force. Experience and practices adopted for different types of soil erosion: Engineering measures: For erosion ditches, the protection modes and treatment measures such as ditch head protection, ditch bank protection, willow pile revetment, slope cutting, grid slope protection, stone valley square, earth willow valley square, and pulp masonry drainage ditch are mainly adopted. Tillage measures: For slope cultivated land, control measures such as horizontal ridge tillage, high tillage such as downhill slope, ridge crop area field, and ridge plant belt, as well as protective tillage measures such as rotational tillage fallow, no-tillage, and less tillage are adopted. Natural restoration measures: restoration of artificial vegetation in degraded saline-alkali land, construction of vegetation buffer zones along river banks, and return of farmland on slopes to forests and grasslands.

People's Daily Online: In order to prevent soil erosion from reducing the area of cultivated land, soil fertility, and crop yields, what do you think farmers should pay attention to in the process of farming?

In view of the control of soil erosion, it is necessary to pay attention to land leveling, high-standard farmland construction, change the planting of slopes to mechanical ridges and horizontal planting, fully apply key technologies of soil erosion such as horizontal ridges, ridge cropping area fields, pasture belts, and dungs, improve farmland water conservancy supporting facilities, and promote water-saving irrigation technologies; in view of the decline in soil fertility and the reduction of crop yields, it is necessary to pay attention to the state of soil fertility, implement soil testing formula fertilization, accumulate and apply organic fertilizers such as farm manure, reduce the amount of chemical fertilizer application, and combine protective tillage. Fallow rotation and other methods have been deeply promoted to implement straw return to the field to reduce the anthropogenic loss of nutrients in farmland. In the practice of farming, we actively explore the application of new technologies and methods such as biological measures, engineering measures and tillage measures to improve the ability of soil to retain water and fertilizer, and reduce soil erosion and nutrient loss in the process of tillage. Firmly establish the idea of sustainable utilization of protection and utilization among the vast number of farmers, and comprehensively promote the implementation of technical models such as soil testing and formula fertilization, conservation tillage and straw mulching.

People's Daily Online: Black land is a valuable non-renewable resource, in the next step, how do you think Jilin Province should achieve sustainable use of black soil resources while ensuring food security?

Coordinate production factors such as soil, water, fertilizer and cultivation, and comprehensively apply engineering, agronomy, agricultural machinery, biology and other technologies and measures. In accordance with the requirements of farmland grading and zoning classification and control, differentiated utilization and protection measures are adopted for the quality level of cultivated land to ensure that black land protection achieves practical results. Vigorously promote the accumulation and utilization of organic fertilizers: promote the crushing of straw and deep ploughing and return to the field, cover no-tillage return, over-belly conversion and return to the field, effectively use livestock and poultry breeding wastes, etc., accumulate and apply organic fertilizers, increase soil organic matter content, and improve the fertility of cultivated land. Promote conservation tillage models: Implement conservation tillage modes such as no-tillage and low tillage, straw mulching and returning farmland, straw whole plant returning seedlings with rotational fallowing, and promote no-tillage and strip farming agricultural machinery suitable for straw return conditions. Promote the application of chemical fertilizer and pesticide reduction technology: implement soil testing formula fertilization and mechanized precision fertilization spraying, comprehensively promote the integration of efficient new fertilizers and water and fertilizers; promote the application of efficient and low-toxicity biological pesticides and green prevention and control technologies for diseases and insect pests, and improve the ecological environment of farmland. Promote soil erosion control: Comprehensively promote the construction of high-standard farmland, strengthen the comprehensive treatment of slope cultivated land, improve farmland water conservancy facilities and irrigation technology, comprehensively control soil and nutrient loss, and ensure the sustainable use of water and soil resources. Develop a seed-breeding integrated circular agriculture model: take the planting and breeding industry as a whole, increase the multi-channel comprehensive utilization of straw, organic fertilizer production and other links, extend the industrial chain, and form the resource and material recycling of all aspects of planting and aquaculture production. Promote the protection of black soil and the effective use of resources through industrial development, improve economic and ecological benefits, drive rural economic development, and realize the sustainable use of black soil resources.